1. Field of the Invention
This invention relates to a sewing machine in which a moving speed at which a thread cassette having a supply of thread is attached to a sewing machine body is limited.
2. Description of the Related Art
There have conventionally been provided sewing machines in which a thread cassette accommodating a supply of thread such as a thread spool is attached to a cassette mount provided in a sewing machine body. A user moves the thread cassette to attach the latter to the cassette mount. In this case, it is preferable that the thread cassette should be moved properly.
However, the user sometimes attaches the thread cassette to the cassette mount at a stroke. Thus, when the moving speed of the thread cassette exceeds a proper one, the thread cassette and/or the cassette mount may be damaged or broken due to a shock during attachment, or equipment installed in the sewing machine for sewing or sewing preparation may be broken.
Furthermore, in sewing machines including a threading mechanism operated in synchronization with attachment of the tread cassette, an operating force from the thread cassette is sometimes transmitted via an operating force transmitting member to the threading mechanism so that the threading mechanism is operated. The transmitting member transmits the operating force from the thread cassette to the threading mechanism. JP-A-2002-191886 discloses one of such sewing machines. In the disclosed sewing machine, the threading mechanism is not sometimes operated properly when the transmitting member moves too quickly. As a result, threading is not sometimes carried out normally, one or more components are sometimes broken or the thread is disturbed.
The foregoing problems also occur in sewing machines in which the operating force from the thread cassette is transmitted via the transmitting member to the thread carrying mechanism during attachment of the thread cassette so that the thread carrying mechanism is operated. Thus, when the transmitting member moves too quickly in these sewing machines, the thread carrying mechanism is operated at a higher speed than a normal operating speed such that the one or more components are sometimes broken or the thread is disturbed.